Sure! Dual drivers will be up to 6 dB louder and require 2x the pipe Vb, while compound drivers will dramatically reduce the required pipe Vb, which is only a 'good thing' with drivers that require huge cabs. Also, due to depth limitations they will have to be clamhell mounted, relegating them to sub duty.

Yes, though its placement will make it impractical AFAIK unless mounted internally like Danley Soundlab's Tower Of Power sub.

GM

__________________Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.

Talking of dual drivers I have a set of drivers/crossovers for a pair of Ariels (MTM) sitting around and was thinking of puting them in a BIB. I had assumed from what I had read that means doubling the mouth area to effetively double the volume to allow for the Vas being doubled. Length would stay the same for that driver??

Regards driver position, distance from top of cab - would you use the mid point between the drivers?

You're answers were what I thought to myself but I was not sure which is why I rather ask and hear (read) from those like yourself who know. So with the driver configuration changes, a BIB pretty much responds in a similar fashion as a BR.

Andrew

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Maybe GM could explain well the maximum distance from the ceiling and its interaction. But I think you can play with the position from corners and rear walls to balance the response. Anyway, having the mouth closer to the ceiling it's more or less like an inverted BIB using the floor....

Well, I did say they'd be a little large... The line length is not exactly length /2, but that gets you close enough, though there's an excellent spreadsheet available on the thread & elsewhere that makes a good partner to Greg's that helps you calc the exact cabinet height for a given line length.

Chris -funny you should mention an Ariel BIB. I did a cabinet for these a while back, but I can't find it anymore, so I re-ran the sim:

The internal height of the cab I calculated as 80" [if line length is a path bisecting the front and

internal baffles, a semi-circle around the bottom of the internal baffle, plus the thickness of that

baffle, then upward, bisecting internal and rear baffles.]

I included a 3/4'' base that would be included inside of the cab, [if that makes sense, that would

be temporarily screwed in place as per Scotts' recommendation], and then that whole thing

sitting on a 2" granite or marble base.

I don't think I screwed up the measurements.

John.

Hi John,
I don't know.... I'm putting on paper my BIB, but before that, I've tried to draw the dims straight on the plywood 1:1 scale to measure and check the dimensions. Start with L/2 and placed the internal baffle with different thickness wood, I measured very little difference between the oblique line and the straight one (not even 5mm!). Then I considered the semicircle path and made the adjustment...
So I consider 80" internal much longer than it should be....

It make sense that your speakers rise up using the marble bases, but be aware of marble and similar, in my experience when I tried granite and marble under my turntable, the sound got worse! And it was possible to hear different sound from different marbles. So I turn ed to thick plywood instead, as long as a friend of mine made some astonishing platforms.